In recent years, it has become easier to carry personal information or confidential information of a company and to utilize such information anywhere, as a result of the spread of compact information terminals such as laptop personal computers, Personal Digital Assistants (PDA), and mobile phones. However, more and more information leak cases are occurring due to information terminals, such as laptop personal computers and compact information terminals, being lost or stolen.
Generally, as one of the methods for preventing information leakage from an information terminal such as a laptop personal computer or a compact information terminal which is lost or stolen, there is a method of deleting information in the terminal by remotely operating the terminal from a remote location via a wired or wireless connection (see Patent Literature (PTL) 1, for example).
In the subsystem for preventing illicit use of radio portable terminal disclosed in PTL 1, an owner of a stolen radio portable terminal issues a stolen notification from another terminal to an information center where portable terminals are administrated, and the information center wirelessly sends a system lock request to the target terminal in response to the notification. Then, the internal data on the stolen portable terminal is deleted.
Thus, a third party cannot access a wireless network nor view the internal data, such as an address list, after the portable terminal is lost or stolen. Therefore, the security of the portable terminal is maintained.